On Thu, Nov 30, 2023 at 02:52:10PM -0600, Gustavo A. R. Silva wrote: > -Wstringop-overflow is buggy in GCC-11. Therefore, we should disable Can you add some links for this? For example, maybe this? https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97490 Or discussions from -next builds? > this option specifically for that compiler version. To achieve this, > we introduce a new configuration option: GCC11_NO_STRINGOP_OVERFLOW. > > The compiler option related to string operation overflow is now managed > under configuration CC_STRINGOP_OVERFLOW. This option is enabled by > default for all other versions of GCC that support it. > > Signed-off-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx> But yeah, let's get this landed to keep new warnings from appearing... Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx> > --- > Makefile | 4 +++- > init/Kconfig | 12 ++++++++++++ > 2 files changed, 15 insertions(+), 1 deletion(-) > > diff --git a/Makefile b/Makefile > index 2cfd71ae3a86..8adc611fb611 100644 > --- a/Makefile > +++ b/Makefile > @@ -982,7 +982,9 @@ NOSTDINC_FLAGS += -nostdinc > # perform bounds checking. > KBUILD_CFLAGS += $(call cc-option, -fstrict-flex-arrays=3) > > -KBUILD_CFLAGS += $(call cc-option, -Wstringop-overflow) > +#Currently, disable -Wstringop-overflow for GCC 11, globally. > +KBUILD_CFLAGS-$(CONFIG_CC_NO_STRINGOP_OVERFLOW) += $(call cc-option, -Wno-stringop-overflow) > +KBUILD_CFLAGS-$(CONFIG_CC_STRINGOP_OVERFLOW) += $(call cc-option, -Wstringop-overflow) > > # disable invalid "can't wrap" optimizations for signed / pointers > KBUILD_CFLAGS += -fno-strict-overflow > diff --git a/init/Kconfig b/init/Kconfig > index 9ffb103fc927..aaaa99a5d2a9 100644 > --- a/init/Kconfig > +++ b/init/Kconfig > @@ -876,6 +876,18 @@ config CC_NO_ARRAY_BOUNDS > bool > default y if CC_IS_GCC && GCC_VERSION >= 110000 && GCC11_NO_ARRAY_BOUNDS > > +# Currently, disable -Wstringop-overflow for GCC 11, globally. > +config GCC11_NO_STRINGOP_OVERFLOW > + def_bool y > + > +config CC_NO_STRINGOP_OVERFLOW > + bool > + default y if CC_IS_GCC && GCC_VERSION >= 110000 && GCC_VERSION < 120000 && GCC11_NO_STRINGOP_OVERFLOW > + > +config CC_STRINGOP_OVERFLOW > + bool > + default y if CC_IS_GCC && !CC_NO_STRINGOP_OVERFLOW > + > # > # For architectures that know their GCC __int128 support is sound > # > -- > 2.34.1 > -- Kees Cook
